Approximately 8.2 million (3.3%) of Americans e 12 years of age are current smokeless tobacco (ST) users, and the prevalence of ST use has increased over the past three years. ST is increasingly being promoted as a harm reduction strategy for cigarette smoking, and two of the world's largest cigarette manufacturers have entered the ST market. ST use is estimated to be the greatest exogenous source of human exposure to cancer-causing nitrosamines. ST has been associated with oral and extra-oral cancer as well as cardiovascular and cerebrovascular mortality. A need for efficacious interventions exists as 64% of ST users report the desire to quit. However, no pharmacotherapy has proven efficacy for increasing long-term (>6 months) tobacco abstinence rates among ST users compared to placebo. New pharmacotherapies, drug combinations, and improved dosing of existing pharmacotherapies are needed. Previous research with nicotine patches for ST users using standard doses (up to 21 mg/day) have not increased long-term abstinence rates. However, studies of higher dose nicotine patch therapy (up to 63 mg/day) in ST users have demonstrated a dose-dependent reduction in tobacco withdrawal symptoms as well as preliminary evidence of increased long-term (>6 months) abstinence rates compared to lower doses. The assessment of the efficacy of high dose nicotine patch therapy for increasing long-term ST abstinence rates in a pilot study is the next logical and necessary step to advance research in the field of interventions for ST users. Our long-term objective is to develop and test effective pharmacotherapies that can be used clinically to increase tobacco abstinence rates among ST users. The primary aim of the current trial is to evaluate the efficacy of high dose nicotine patch therapy (42 mg/day) for increasing the 7-day point prevalence and prolonged all tobacco and ST abstinence rates at end-of-treatment (week 8), 12 and 24 weeks compared to placebo in ST users who use e 3 cans/pouches per week when all subjects receive behavioral treatment for tobacco dependence. To accomplish our aims, we will randomize 60 ST users in a clinical pilot study. The work will be conducted at the Mayo Clinic in Rochester, MN. PUBLIC HEALTH RELEVANCE: Smokeless tobacco use ("chewing") is associated with negative health effects. To date, no medications have been shown to help chewers quit long-term. High dose nicotine patch therapy may improve the chances that chewers can quit for good. If found to be effective, chewers may use this treatment to help them quit and reduce their risk for negative health effects.